FVXX22 KWBC 280430 VOLCANIC ASH ADVISORY STATEMENT ISSUED 0430 UTC 28 NOV 1999 BY THE WASHINGTON VAAC . SAN CRISTOBAL 99-008 NICARAGUA 12.7N 87.0W . BACKGROUND: SAN CRISTOBAL NICARAGUA (1404-02) SUMMIT HEIGHT 5725 FT (1745 M) . SOURCES OF INFORMATION: GOES-8 INFRARED AND MULTISPECTRAL IMAGERY...1800 UTC AVIATION MODEL WIND FORECAST . ERUPTION DETAILS: SATELLITE IMAGERY SUGGESTED A POSSIBLE SMALL ERUPTION BEGINNING AROUND 1900 UTC. . DETAILS OF ASH CLOUD: NO ASH CAN BE DETECTED IN GOES-8 INFRARED AND MULTISPECTRAL SATELLITE IMAGERY THROUGH 28/0345 UTC. A FEW HOURS AGO MID LEVEL WEATHER CLOUDS MOVED INTO THE AREA BUT EVEN BEFORE THESE CLOUDS ARRIVED NO ASH COULD BE SEEN IN IMAGERY. HOWEVER SINCE THE LOW LEVEL ASH WAS PREVIOUSLY SEEN ONLY IN VISIBLE IMAGERY IT IS POSSIBLE THAT THIS ASH STILL EXISTS BUT CAN NO LONGER BE SEEN AT NIGHT IN THE ABSENCE OF VISIBLE SATELLITE IMAGERY. . TRAJECTORY: UPPER AIR PATTERNS SUGGEST THAT ANY ASH AT ABOUT FL070 WOULD MOVE TO THE SOUTHWEST AT ABOUT 20 KNOTS. . REAL TIME SATELLITE IMAGERY ALONG WITH THIS AND OTHER VOLCANIC ASH ADVISORY STATEMENTS OFTEN ACCOMPANIED BY A MAP DEPICTING ASH LOCATION ARE AVAILABLE AT INTERNET URL ADDRESS www.ssd.noaa.gov/VAAC/washington.html (all lower case except /VAAC/) . OUTLOOK: SEE LATEST SIGMETS. . THIS WILL BE THE LAST MESSAGE ON THIS EVENT UNLESS NEW INFORMATION IS RECEIVED. . PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS. . NNNN